Foam donut cutting machine
 

Hi

I need to find an alternative to true tyres for 8th scale. I race pan car and use tyres below 68mm. Truing down from 80mm takes AGES, burnt fuses and dull cutters.

I came across this video and I would like to arrange a similar solution. Anyone who already made it before me? Any idea to help? What cutter should be used?

Any help is much appreciated!!

here is another video of a similar machine

unfortunately this is no longer available to purchase new. its an interesting concept...

That's exactly what I'd like to do. I can do it and already do it in 12th scale with a press drill and a little cutter in the vice. But 8th scale tyres are different animals. The cutter in the video seems strong enough, though.

Maybe some Japanese speaking friends could translate the subtitles?...

Thanks for the vid. It seems the machine is from morotech, I'll look into that

In the video I posted it's a Cross CR906

https://cimg6.ibsrv.net/gimg/www.rct...a28b53166b.jpg

I have a cross donut cutter similar to what's posted with the linear bearing rails. I bought it through a friend who lives in Japan. I think I paid $200 plus shipping for it. If you're interested in it PM me. I don't need to get what I spent for it.

Hey Andrew, you got pm

Thanks a lot. I'll keep that in mind!

Any luck figuring out what cutter is used? I have looked everywhere google leads me to find something similar to no avail :( I just need to source the cutting bit.

there are the best pics i've seen of the cross cutting bit--

https://cimg1.ibsrv.net/gimg/www.rct...d97ea53dd6.jpg
https://cimg2.ibsrv.net/gimg/www.rct...bf352a3078.jpg

I have a maxmod with that cutter and all the attachments for 1/12th and F1/TC.. It is a heavy duty machine that he built for me back in the day.I mounted my own tires back then and my maximod was not powerdful enough. It got hot so he built this one for me. I dont use it any more.I have and 1/8th tire and I'll see if it will work later today.

Looks like a drill blank with the angle ground onto the end. Should be able to order the blank from one of the tool suppliers like McMaster-Carr and grind the cutting edge yourself with a bench grinder.

any brand still makes this similar tool?

Or a Dremel with a cutting disc.

I agree, just a length of cobalt drill blank, be aware there are different grades of cobalt and HSS drill blanks, I used this same method for Line Boring equipment bearing and pin bores after welding bad bores undersized, Prior to hand grinding the desired profile to the end of said drill blank, I would grind a flat on the length to align for proper orientation.
nice feature is quite simple to refresh the cutting point as it dulls and wears.